2002 JEEP LIBERTY ECU

A wiper arm cannot be adjusted or repaired. If
damaged or faulty, the entire wiper arm unit must be
replaced.
OPERATION
The rear wiper arm is designed to mechanically
transmit the motion from the rear wiper motor out-
put shaft to the rear wiper blade. The wiper arm
must be properly indexed to the motor output shaft
in order to maintain the proper wiper blade travel on
the glass. The wiper arm support is designed to lift
and support the rear wiper arm and blade off of the
glass when the rear wiper blade is parked. This sup-
port and the park ramp on the tailgate outer panel
below the glass also provide an alignment reference
to ensure accurate rear wiper arm and blade instal-
lation. The tapered hole in the wiper arm pivot end
is interlocks with the serrations on the outer circum-
ference of the tapered motor output shaft, allowing
positive engagement and finite adjustment of this
connection. A hex nut secures the wiper arm pivot
end to the threads on the rear wiper motor output
shaft and the pivot cover hinges and snaps over this
connection for a neat appearance. The spring-loaded
wiper arm hinge controls the down-force applied
through the tip of the wiper arm to the wiper blade
on the glass. The hook formation on the tip of the
wiper arm provides a cradle for securing and latching
the wiper blade pivot block to the wiper arm.
REMOVAL
(1) Lift the rear wiper arm pivot cover by lifting it
at the rear wiper motor output shaft end of the arm
(Fig. 9).
(2) Remove the nut that secures the rear wiper
arm to the rear wiper motor output shaft.
(3) If necessary, use a battery terminal puller to
disengage the wiper arm from the rear wiper motor
output shaft splines (Fig. 10).
NOTE: Depending upon the size and type of puller
used, it may be necessary to remove the spare tire
from the tailgate. Refer to the owner's manual in the
vehicle glove box for information on removing the
spare tire from the tailgate.
(4) Remove the rear wiper arm pivot end from the
motor output shaft.
INSTALLATION
NOTE: Always install the wiper arm and blade with
the wiper motor in the Park position.
(1) The rear wiper arm must be indexed to the
motor output shaft with the rear wiper motor in the
park position to be properly installed. Place thewiper arm onto the tailgate with the wiper arm sup-
port positioned on the park ramp and the tapered
mounting hole on the pivot end of the arm positioned
over the rear wiper motor output shaft.
(2) Position the tab on the back of the rear wiper
arm support on the tailgate park ramp in the Instal-
lation Position (Fig. 11).
(3) With the wiper arm in the Installation Posi-
tion, push the tapered mounting hole on the pivot
end of the wiper arm down over the rear wiper motor
output shaft.
Fig. 9 Rear Wiper Arm Remove/Install
1 - SPARE TIRE
2 - WRENCH
3 - FLIP-UP GLASS
4 - PARK RAMP
5 - REAR WIPER ARM
6 - PIVOT COVER
Fig. 10 Wiper Arm Puller - Typical
1 - WIPER ARM
2 - WIPER PIVOT
3 - BATTERY TERMINAL PULLER
8R - 38 REAR WIPERS/WASHERSKJ
REAR WIPER ARM (Continued)

(4) Install and tighten the nut that secures the
rear wiper arm to the rear wiper motor output shaft.
Tighten the nut to 18 N´m (13 ft. lbs.).
(5) Close the rear wiper arm pivot cover.
(6) Lift the rear wiper arm support away from the
park ramp, then place the wiper arm support in the
park ramp in the Park Position (Fig. 11).
REAR WIPER BLADE
DESCRIPTION
The rear wiper blade is secured by an integral
latching pivot block to the hook formation on the tip
of the rear wiper arm, and rests off the glass on a
park ramp on the tailgate near the base of the rear
flip-up glass opening when the wiper is not in oper-ation (Fig. 12). The rear wiper blade consists of the
following components:
²Superstructure- The superstructure includes
a stamped steel bridge and plastic links with claw
formations that grip the wiper blade element. Also
included in this unit is the latching, molded plastic
pivot block that secures the superstructure to the
wiper arm. All of the metal components of the wiper
blade have a satin black finish applied.
²Element- The wiper element or squeegee is the
resilient rubber member of the wiper blade that con-
tacts the glass.
²Flexor- The flexor is a rigid metal component
running along the length of each side of the wiper
element where it is gripped by the claws of the
superstructure.
All models have a single 28.00 centimeter (11.00
inch) rear wiper blade with a non-replaceable rubber
element (squeegee). The wiper blade cannot be
adjusted or repaired. If faulty, worn, or damaged the
entire wiper blade unit must be replaced.
OPERATION
The wiper blade is moved back and forth across the
glass by the wiper arm when the wiper system is in
operation. The wiper blade superstructure is the flex-
ible frame that grips the wiper blade element and
evenly distributes the force of the spring-loaded
wiper arm along the length of the element. The com-
bination of the wiper arm force and the flexibility of
the superstructure makes the element conform to
Fig. 11 Rear Wiper Arm Installation
1 - TAILGATE
2 - PARK RAMP
3 - REAR WIPER ARM
4 - INSTALLATION POSITION
5 - REAR WIPER ARM AND BLADE
6 - PARK POSITION
7 - PARK RAMP
8 - TAILGATE
Fig. 12 Rear Wiper Blade
1 - SUPERSTRUCTURE
2 - PIVOT PIN
3 - LATCH RELEASE
4 - PIVOT BLOCK
5 - CLAW
6 - FLEXOR
7 - ELEMENT
KJREAR WIPERS/WASHERS 8R - 39
REAR WIPER ARM (Continued)

(3) Raise the pivot block latch release tab until it
is perpendicular to the rear wiper blade superstruc-
ture (Fig. 14).
(4) Insert the hook formation on the tip of the
wiper arm through the window in the wiper blade
pivot block/latch unit.
(5) Slide the wiper blade pivot block/latch up into
the hook formation on the tip of the wiper arm until
the hook is firmly seated against the pivot block.
(6) Press the pivot block latch release tab down-
ward until it snaps into its locked position over the
top of the wiper arm.
(7) Gently lower the wiper arm and place the arm
support in the tailgate park ramp.
REAR WIPER MOTOR
DESCRIPTION
The rear wiper motor is concealed within the tail-
gate, below the rear flip-up glass opening and behind
the tailgate inner trim panel. The end of the motor
output shaft that protrudes through the tailgate
outer panel to drive the rear wiper arm and blade is
the only visible component of the rear wiper motor
(Fig. 15). A rubber gasket, a bezel, and a nut secure
and seal the motor output shaft to the tailgate outer
panel. A molded plastic nut cover snaps onto the
bezel to conceal the nut and improve appearance. An
integral connector receptacle connects the rear wipermotor to the vehicle electrical system through a ded-
icated take out and connector of the tailgate wire
harness. The rear wiper motor consists of the follow-
ing major components:
²Bracket- The rear wiper motor bracket consists
of a stamped steel mounting plate for the wiper
motor that is secured with screws through two rub-
ber insulators to the tailgate inner panel.
²Rear Wiper Module- The rear wiper motor
electronic controls are concealed beneath a molded
plastic cover and includes the rear wiper system elec-
tronic logic and rear wiper motor electronic controls.
²Motor- The permanent magnet rear wiper
motor is secured with screws to the rear wiper motor
bracket. The wiper motor includes an integral trans-
mission, and the motor output shaft.
The rear wiper motor cannot be adjusted or
repaired. If any component of the motor is faulty or
damaged, the entire rear wiper motor unit must be
replaced. The motor output shaft gasket, bezel, nut,
and nut cover are available for service replacement.
OPERATION
The rear wiper motor receives non-switched bat-
tery current through a fuse in the Junction Block
(JB) on a fused B(+) circuit and is connected to
ground at all times. The rear wiper motor operation
is controlled by the vehicle operator through battery
current signal inputs received by the rear wiper
motor electronic control module from the rear wiper
switch circuitry that is integral to the right (wiper)
control stalk of the multi-function switch on the
steering column. The module also receives an exter-
nal control input from the flip-up glass ajar switch
sense circuit. If the rear wiper module senses that
the flip-up glass is ajar, it will not allow the rear
wiper motor to operate.
The rear wiper module electronic control logic uses
these inputs, its internal inputs, and its program-
ming to provide a continuous wipe mode, an inter-
mittent wipe mode, a wipe-after-wash mode, and off-
the-glass wiper blade parking. The wiper blade
cycling is controlled by the internal electronic con-
trols of the module. The module controls current flow
to the wiper motor brushes and provides an elec-
tronic speed control that speeds the wiper blade near
the center of the glass, but slows the wiper blade
during directional reversals at each end of the wipe
pattern and during wiper blade off-the-glass parking
for quieter operation. The wiper motor transmission
converts the rotary output of the wiper motor to the
back and forth wiping motion of the rear wiper arm
and blade on the rear flip-up glass.
Fig. 15 Rear Wiper Motor
1 - SCREW (2)
2 - INSULATOR (2)
3 - BRACKET
4 - OUTPUT SHAFT
5 - SEAL
6 - CONNECTOR RECEPTACLE
7 - COVER
8 - MOTOR
KJREAR WIPERS/WASHERS 8R - 41
REAR WIPER BLADE (Continued)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear wiper arm from the rear
wiper motor output shaft. (Refer to 8 - ELECTRI-
CAL/REAR WIPERS/WASHERS/REAR WIPER ARM
- REMOVAL).
(3) Using a small thin-bladed tool, gently pry at
the notch in the base of the rear wiper motor output
shaft bezel to unsnap the nut cover from the bezel
(Fig. 16).Be certain to take proper precautions
to protect the outer tailgate panel and its paint
finish from damage during this procedure.
(4) Remove the nut that secures the rear wiper
motor output shaft to the outer swing gate panel
(Fig. 16).
(5) Remove the bezel and gasket from the rear
wiper motor output shaft.
(6) Remove the trim panel from the tailgate inner
panel. (Refer to 23 - BODY/SWING GATE/TRIM
PANEL - REMOVAL).
(7) Disconnect the tailgate wire harness connector
for the flip-up glass ajar switch from the flip-up glass
latch connector receptacle.
(8) Disconnect the tailgate wire harness connector
for the rear wiper motor from the motor connector
receptacle (Fig. 17).
(9) Loosen the two screws that secure the rear
wiper motor mounting bracket to the top of the tail-
gate inner panel.
(10) Slide the rear wiper motor and mounting
bracket back far enough to disengage the two mount-ing screws from the keyed slots in the top of the tail-
gate inner panel.
(11) Remove the rear wiper motor and mounting
bracket from the tailgate as a unit.
INSTALLATION
(1) Position the rear wiper motor and bracket into
the tailgate as a unit (Fig. 17).
(2) Insert the rear wiper motor output shaft
through the hole in the tailgate outer panel and
engage the two mounting screws into the keyed slots
in the top of tailgate inner panel.
(3) From the outside of the tailgate, center the
rear wiper motor output shaft in the tailgate outer
panel clearance hole and install the gasket and bezel
over the centered shaft (Fig. 16).
(4) Install and tighten the nut that secures the
rear wiper motor output shaft to the outer tailgate
panel. Tighten the nut to 5 N´m (43 in. lbs.).
(5) From the inside of the tailgate, tighten the two
screws that secure the rear wiper motor mounting
bracket to the top of the tailgate inner panel. Tighten
the screws to 6 N´m (57 in. lbs.).
(6) Reconnect the tailgate wire harness connector
for the rear wiper motor to the motor connector
receptacle.
Fig. 16 Rear Wiper Motor Output Shaft Nut
Remove/Install
1 - BEZEL AND GASKET
2 - OUTPUT SHAFT
3 - TAILGATE OUTER PANEL
4 - NUT
5 - NUT COVER
Fig. 17 Rear Wiper Motor Remove/Install
1 - KEYED SLOT (2)
2 - SWING GATE INNER PANEL
3 - SCREW (2)
4 - REAR WIPER MOTOR ELECTRICAL CONNECTOR
5 - REAR WIPER MOTOR
8R - 42 REAR WIPERS/WASHERSKJ
REAR WIPER MOTOR (Continued)

(7) Reconnect the tailgate wire harness connector
for the flip-up glass ajar switch to the flip-up glass
latch connector receptacle.
(8) Reinstall the trim panel onto the tailgate inner
panel. (Refer to 23 - BODY/SWING GATE/TRIM
PANEL - INSTALLATION).
(9) From the outside of the tailgate, press the nut
cover firmly and evenly over the rear wiper motor
output shaft bezel using hand pressure until it snaps
into place.
(10) Reinstall the rear wiper arm onto the rear
wiper motor output shaft. (Refer to 8 - ELECTRI-
CAL/REAR WIPERS/WASHERS/REAR WIPER ARM
- INSTALLATION).
(11) Reconnect the battery negative cable.
REAR WIPER/WASHER
SWITCH
DESCRIPTION
The rear wiper and washer switches are integral to
the right (wiper) control stalk of the multi-function
switch. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
DESCRIPTION).
OPERATION
The rear wiper and washer switches are integral to
the right (wiper) control stalk of the multi-function
switch. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
OPERATION).
WIPER ARM PARK RAMP
REMOVAL
(1) Disengage the rear wiper arm support from the
wiper arm park ramp on the right side of the tailgate
just below the rear flip-up glass.(2) Lift the wiper arm and blade away from the
tailgate until the wiper arm hinge is in its over-cen-
ter position.
Remove the screw that secures the wiper arm park
ramp to the tailgate outer panel (Fig. 18).
(3) Remove the wiper arm park ramp from the
tailgate outer panel.
INSTALLATION
(1) Position the wiper arm park ramp onto the
tailgate outer panel (Fig. 18).
(2) Install and tighten the screw that secures the
wiper arm park ramp to the tailgate outer panel.
Tighten the screw to 5 N´m (45 in. lbs.).
(3) Lower the rear wiper arm and blade and place
the wiper arm support onto the wiper arm park
ramp.
Fig. 18 Wiper Arm Park Ramp Remove/Install
1 - SCREW (1)
2 - PARK RAMP
3 - RIVET NUT (1)
4 - TAILGATE OUTER PANEL
KJREAR WIPERS/WASHERS 8R - 43
REAR WIPER MOTOR (Continued)

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION...... 8Wa-01-1
COMPONENT INDEX................. 8Wa-02-1
POWER DISTRIBUTION.............. 8Wa-10-1
JUNCTION BLOCK................... 8Wa-12-1
GROUND DISTRIBUTION............. 8Wa-15-1
BUS COMMUNICATIONS............. 8Wa-18-1
CHARGING SYSTEM................. 8Wa-20-1
STARTING SYSTEM................. 8Wa-21-1
FUEL/IGNITION SYSTEM............. 8Wa-30-1
TRANSMISSION CONTROL SYSTEM.... 8Wa-31-1
VEHICLE SPEED CONTROL........... 8Wa-33-1
ANTILOCK BRAKES.................. 8Wa-35-1
VEHICLE THEFT SECURITY SYSTEM.... 8Wa-39-1
INSTRUMENT CLUSTER.............. 8Wa-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . 8Wa-41-1
AIR CONDITIONING-HEATER.......... 8Wa-42-1
AIRBAG SYSTEM................... 8Wa-43-1
INTERIOR LIGHTING................. 8Wa-44-1BODY CONTROL MODULE............ 8Wa-45-1
AUDIO SYSTEM.................... 8Wa-47-1
REAR WINDOW DEFOGGER........... 8Wa-48-1
OVERHEAD CONSOLE................ 8Wa-49-1
FRONT LIGHTING................... 8Wa-50-1
REAR LIGHTING.................... 8Wa-51-1
TURN SIGNALS..................... 8Wa-52-1
WIPERS........................... 8Wa-53-1
TRAILER TOW...................... 8Wa-54-1
POWER WINDOWS.................. 8Wa-60-1
POWER DOOR LOCKS............... 8Wa-61-1
POWER MIRRORS.................. 8Wa-62-1
POWER SEAT...................... 8Wa-63-1
POWER SUNROOF.................. 8Wa-64-1
SPLICE INFORMATION............... 8Wa-70-1
CONNECTOR PIN-OUTS.............. 8Wa-80-1
CONNECTOR/GROUND/
SPLICE LOCATION................. 8Wa-91-1 KJWIRING
8Wa-1

8W-39 VEHICLE THEFT SECURITY SYSTEM
Component Page
Body Control Module......... 8Wa-39-2, 3, 4, 5, 9
Clockspring........................ 8Wa-39-5
Clutch Switch Override Relay.......... 8Wa-39-2
Compass Mini-Trip Computer.......... 8Wa-39-8
Diagnostic Junction Port............ 8Wa-39-6, 8
Flip-Up Glass Release Switch.......... 8Wa-39-4
Fuse 3............................ 8Wa-39-5
Fuse 7............................ 8Wa-39-2
Fuse 13......................... 8Wa-39-2, 8
Fuse 14........................... 8Wa-39-2
Fuse 15........................... 8Wa-39-6
Fuse 28........................... 8Wa-39-2
Fuse 32........................... 8Wa-39-2
Fuse 33........................... 8Wa-39-6
Fuse 34....................... 8Wa-39-2, 7, 8
G111 ........................... 8Wa-39-5, 7
G202............................. 8Wa-39-6
G300............................. 8Wa-39-3
G302............................. 8Wa-39-3
G311 ............................. 8Wa-39-8
High Note Horn.................... 8Wa-39-5Component Page
Hood Ajar Switch................... 8Wa-39-5
Horn Relay........................ 8Wa-39-5
Horn Switch....................... 8Wa-39-5
Ignition Switch..................... 8Wa-39-2
Intrusion Sensor.................. 8Wa-39-7, 8
Junction Block............ 8Wa-39-2, 5, 6, 7, 8, 9
Left Cylinder Lock Switch............. 8Wa-39-9
Left Door Lock Switch................ 8Wa-39-9
Left Front Door Lock Motor/Ajar Switch . . 8Wa-39-3
Left Rear Door Lock Motor/Ajar Switch . . 8Wa-39-3
Low Note Horn..................... 8Wa-39-5
Power Distribution Center............ 8Wa-39-2
Right Cylinder Lock Switch........... 8Wa-39-9
Right Door Lock Switch.............. 8Wa-39-9
Right Front Door Lock Motor/Ajar Switch . 8Wa-39-3
Right Rear Door Lock Motor/Ajar Switch . 8Wa-39-3
Sentry Key Immobilizer Module........ 8Wa-39-6
Siren............................. 8Wa-39-7
Starter Motor Relay................. 8Wa-39-2
Tailgate Cylinder Lock Switch......... 8Wa-39-4
Tailgate Lock Motor/Ajar Switch........ 8Wa-39-4
KJ8W-39 VEHICLE THEFT SECURITY SYSTEM8Wa-39-1

CONDITION POSSIBLE CAUSES CORRECTION
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
3. Incorrect ring size installed. 3. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
4. Worn valve guides. 4. Ream guides and replace valves
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
5. Leaking valve guide seals. 5. Replace valve guide seals.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(5) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(6) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(7) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylin-
ders.
(8) (Refer to 9 - ENGINE - SPECIFICATIONS) for
the correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner.
(6) Calibrate the tester according to the manufac-
turer's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
Set piston of cylinder to be tested at TDC compres-
sion,While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to CYLINDER COMBUSTION PRESSURE
LEAKAGE DIAGNOSIS CHART .
9 - 8 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)